This invention relates to an improved multiple position hydraulic vise jaw that adjusts to accommodate various sized parts.
In the prior art, vise jaws are utilized in conjunction with vises to clamp and hold various parts. In industrial machining operations, vise jaws are utilized to hold one or two parts at one time. The parts are often of similar shape and size, and modern vise jaws are called upon to hold the parts securely.
In the prior art there has been much trouble in holding several parts in that tolerances always result in the parts having slightly different sizes. When there are several parts having slightly different sizes being held, it is not possible for a single clamp surface to adequately hold the several parts with an equal and adequate holding force, i.e., large parts are secure and small parts are lose.
Hydraulic vise jaws are also known wherein a hydraulic fluid selectively biases piston members outwardly from the jaw such that the position of the pistons change to accommodate the shape of the particular part being held. These hydraulic jaws have typically had a separate reservoir for the hydraulic fluid for each row. Therefore, if only one piston in a row was required to hold a part, all the other piston s would extend due to the hydraulic fluid.
It would be desirable to improve the operation of the known hydraulic jaws.
In the disclosed embodiment of this invention, a hydraulic jaw has a series of hydraulic piston cylinders arranged in columns and at least a pair of rows. The hydraulic piston cylinders act as reservoir for a hydraulic fluid. Hydraulic piston elements are received in the hydraulic piston cylinders and are biased outwardly to contact several parts. The pistons can move inwardly or outwardly of the vise jaw body to accommodate varying sizes in the parts being held.
Some prior art hydraulic jaws had a series of rows and columns of pistons. The hydraulic fluid did not connect between the rows, or alternatively, there was an separate reservoir which did not provide equal and adequate force against the rear of the pistons. In the present invention, a small hole connects the hydraulic fluid between the two rows. In this way, the hydraulic fluid is allowed to move between the two rows which maintains an equal and adequate force behind the pistons. In a preferred embodiment, one of the piston cylinders on the top row is connected to one of the piston cylinders on the bottom row which allows the hydraulic fluid to flow between both rows and columns. More preferably, the two piston cylinders are connected in distinct columns such that the hydraulic fluid flow is further regulated. In this way, the force maintained on the rear of the piston is still maintained at a sufficiently high level such that the pistons securely hold the parts.
In another feature, the pistons in each row are held against undue movement by a pin extending through a slot in the piston. The single pin extends from an end surface of the jaw body through slots on the pistons. The pistons are thus allowed to move, while still being restricted against undue movement outwardly from the body. Another advantage of the subject invention allows one or two pistons to operate in a mechanical mode while the remaining pistons are held in a neutral position.
These and other features of the present invention can be best understood from the following specification and drawings, the following which is a brief description.